Silicon etching liquid containing aromatic aldehyde

Abstract

An object of the present invention is to provide an etching liquid having a high silicon etch selectivity with respect to silicon-germanium and a high long term stability at a processing temperature, in surface processing during the production of various semiconductor devices, especially various silicon composite semiconductor devices containing silicon-germanium, and the problem is solved by a silicon etching liquid containing an alkaline compound, an aldehyde compound, and water, the aldehyde compound being a water-soluble aromatic aldehyde.

What is claimed is: 
     
         1 . A silicon etching liquid comprising an alkaline compound, an aldehyde compound, and water, wherein the aldehyde compound is a water-soluble aromatic aldehyde. 
     
     
         2 . The silicon etching liquid according to  claim 1 , wherein the water-soluble aromatic aldehyde is a benzaldehyde derivative. 
     
     
         3 . The silicon etching liquid according to  claim 1 , wherein the alkaline compound is a quaternary ammonium hydroxide. 
     
     
         4 . The silicon etching liquid according to  claim 1 , further comprising an organic solvent. 
     
     
         5 . A method of producing a semiconductor device, the method comprising bringing the silicon etching liquid according to  claim 1  in contact with silicon. 
     
     
         6 . The method of producing a semiconductor device according to  claim 5 , the method comprising bringing the silicon etching liquid in contact with silicon-germanium. 
     
     
         7 . A method of processing silicon wafer, the method comprising bringing the silicon etching liquid according to  claim 1  in contact with a surface of a silicon wafer. 
     
     
         8 . A method of processing a substrate having a silicon film, the method comprising bringing the silicon etching liquid according to  claim 1  in contact with a surface of a substrate having a silicon film.